Method of coloring and finishing the surface of grain-leather



OFFICE.

WYMAN H. MEADE AND SVEN' H. FRIESTEDT, 0F CAMDEN, NEW JERSEY.

METHOD OF COLORTNG AND FINISHING THE SURFACE OF GRAIN-LEATHER.

No Drawing.

T 0 all whom it may concern:

Be it known that we, /VYMAN H. MEADE, a citizen of the United States,and SvEN H. F RIESTEDT, a subject of the King of Sweden, both residingat Camden, county of Gamden, and State of New Jersey, have inventedcertain new and useful Improvements in Methods of Coloring and Finishingthe Surface of Grain-Leather, of which the following is a specification.

It has always been difficult to provlde an even shade of coloring to thesurface of grain leather, especially when light shades of color weredesired. Numerous processes have been devised for securing light evenshades by coating the leather with a heavv coating of pigment, therebygiving the shades but destroying the natural appearance of the grain ofthe leather in view of the fact that in order to cover up any variationin shade of'the natural leather, heavy coatings of the pigment wereapplied, said coatings being of sufficient thickness to fill theinterstices and recesses on the surface of the leather therebydestroying the natural characteristics of the surface of the leather.

One object of our invention is to color and finish the surface of grainleather in such manner that when extremely light color effects areproduced, the color will be even throughout the entire surfaceirrespective of any variation in color of the natural and at the sametime the effect of the natural grain of the leather will not bedestroyed. While we have described the main object as the production oflight color effects, it will be understood however that our process isequally advantageous for dark effects, since even though the variationin color in the old method of coloring is not as noticeable in darkeffects; nevertheless it is noticeable in many instances and by usingour process, variation in shadeof coloring is eliminated for all shadesproduced.

The above objects, and other advantageous ends which will be describedhereinafter, we attain in the following manner.

Our invention consists primarily of applying an element to the surfaceof the leather; the element being secured by precipitation, for example,we take any com- Speeification of Letters Patent.

'alcohol and dry Patented May 3, 1921.

Application filed July 24, 1919. Serial No. 313,006.

pound which is soluble and precipitate an element therefrom. The elementthus precipitated is used as a pigment for applying to the surface ofthe leather. This precipitate can be applied to the grain-side of theleather in any way as a pigment either dry or mixed with a suitablecarrier for covering or coloring the grain of the leather. In view ofthe extreme fineness of the particles of the pigment produced by theprecipitation, the application of this pigment will not destroy the wavyappearance of the leather and any instance where the pigment thusprecipitated is metallic, as will be described hereinafter, there is nochance of transparency so that the finished leather will have the colorof the precipitated pigment applied thereto.

One way of carrying out our invention is as follows Dissolve 249 partsof copper sulfate (CuSO -5H O) in water and add slowly 65 to 70 parts ofzinc-dust Then filter off the precipitated metallic copper, wash freefrom soluble zinc salt. Then'wash it with at room temperature. When dryit is ready to apply to the leather either in dry form or mixed withsome other pigment or carrying agent. One way to do this is as followsTake 50 parts of the element made as above described, mix it with 200parts of casein solution as carrier. Then apply to WYMAN H. MEADE. SVENH. FRIESTEDT.

Witnesses:

CHAS. E. Po'r'rs, ANNA BENTON.

the leather and finish the same in any of the

